Difference between nth and (n+1) the Bohr's radius of 'H' atom is equal ot it s (n-1) th Bohr's radius . The value of n is

Options

A. `1`
B. `2`
C. `3`
D. `4`

Answer

D

Explanation

If `r_(O)` is radius of first orbit of `'H'` atom, then
`r_(n)=(n^(2))/2 r_(O)`
`r_(n+1)=r_(n)=r_(n-1)`
`(n+1)^(2)-n^(2)=(n-1)^(2)`
`n=4`